Otzi, Europe’s oldest mummy, known as The Iceman, likely suffered a head injury before he died roughly 5,300 years ago, according to a new protein analysis of his brain tissue.
Ever since a pair of hikers stumbled upon his astonishingly well-preserved frozen body in the Alps in 1991, Otzi has become one of the most-studied ancient human specimens. His face, last meal, clothing and genome have been reconstructed — all contributing to a picture of Otzi as a 45-year-old, hide-wearing, tattooed agriculturalist who was a native of Central Europe and suffered from heart disease, joint pain, tooth decay and probably Lyme disease before he died.
None of those conditions, however, directly led to his demise. A wound reveals Otzi was hit in the shoulder with a deadly artery-piercing arrow, and an undigested meal in the Iceman’s stomach suggests he was ambushed, researchers say.
A few years ago, a CAT scan showed dark spots at the back of the mummy’s cerebrum, indicating Otzi also suffered a blow to the head that knocked his brain against the back of his skull during the fatal attack.
In the new study, scientists who looked at pinhead-sized samples of brain tissue from the corpse found traces of clotted blood cells, suggesting Otzi indeed suffered bruising in his brain shortly before his death.
But there’s still a piece of the Neolithic murder mystery that remains unsolved: It’s unclear whether Otzi’s brain injury was caused by being bashed over the head or by falling after being struck with the arrow, the researchers say.
The study was focused on proteins found in two brain samples from Otzi, recovered with the help of a computer-controlled endoscope. Of the 502 different proteins identified, 10 were related to blood and coagulation, the researchers said. They also found evidence of an accumulation of proteins related to stress response and wound healing.
A separate 2012 study detailed in the Journal of the Royal Society Interface looked at the mummy’s red blood cells (the oldest ever identified) from a tissue sample taken from Otzi’s wound. That research showed traces of a clotting protein called fibrin, which appears in human blood immediately after a person sustains a wound but disappears quickly. The fact that it was still in Otzi’s blood when he died suggests he didn’t survive long after the injury.
In addition to the proteins related to clotting, Tholey and colleagues also identified dozens of proteins known to be abundant in brain tissue in the samples from Otzi. A microscopic analysis even revealed well-preserved neural cell structures, the researchers said.